Flexible printing-plate.



M. A. DROITO'OUR. FLEXIBLE PRINTING PLATE.

APPLICATION FILED DBO. 23, 190B.

Patented May 31, 1910.

UNITED STAT PAT IT @FFIQE.

MICHAEL A. DROI'ICOUR, OF CHICAGO, ILLINOIS, ASSIGNOR TO MIEHLE PRINTINGPRESS AND MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OFILLINOIS.

FLEXIBLE PRINTING-PLATE.

Specification of Letters Patent. Application filed December 23, 1908.

Patented May 31, 1910. Serial No. 468,938.

To all whom it may concern:

Be it known that I, MICHAEL A. DROIT- coon, a citizen of the UnitedStates, residing in Chicago, in the county of Cook and State ofIllinois, have invented a new and useful Improvement in Fastenings forFlexible Printing-Plates, of which the following is a specification.

This invention relates to the means em ployed for securing flexibleprinting plates to type beds or cylinders, and is intended to accomplishthe same result and a simplification of the devices for the same purposeshown in another application bearing even date herewith.

The nature of the invention and details of the construction thereof arefully set forth below and illustrated in the accompanying drawing inwhich latter- Figure 1 is a side elevation of the invention with theside plates of the end blocks omitted; Fig. 2 is a plan. Fig. 3 is asection on the line 3-3 of Fig. 1, and Fig. 4- a perspective of therocking tightening plate.

In said drawing 5 represents the type bed or the type cylinder uponwhich my inven tion is used, and 6 is the flexible printing plate,having reduced margins 7 at its ends. These margins preferably haveturned up lips 8 running lengthwise of the margins whereby the marginsmay be gripped and securely held. The reduced margins 7 are beyond andbelow the printing surface, and are preferably formed by thinning thematerial of which the plate is made; and this can be done by cutting orchanneling the plate transversely, so as to remove part of the uppersurface thereof and form the reduced margins 7 and the lips 8simultaneously. The reduced margins 7 are preferably bent downwardbefore the plate is placed upon the bed or cylinder, and by reason ofthe thinness of the margins when the plates are tightened the margins 7yield or bend without causing any buckling of the printing surface andthe latter can be stretched very tightly; while the clamping devices arebrought entirely below the line of impression. I propose to make theprinting plates of celluloid or similar composition, and the platemargins and lips may be all of the same material; and it is particularlyimportant when the flexible margins are of the same material as theplate that they should be capable of being bent down I l blocks 9, and11. Of these,

below the impression line without buckling the printing surface of theplate. The plate is supported upon the bed or cylinder by the end ones 9and 10 have along their inward sides a swell or enlargement 12, the topand bottom of which are inclined in opposite directions, and whichengage correspondingly formed surfaces on the center block 11. The formof these enlargements is such as to insure the bringing of the centerand end blocks to the same horizontal plane when they are pressedtogether. The outer edges of the end blocks are cutaway at the top,leaving projecting tongues 13 and 14. In the case of the block 9, asloping surface 15 is provided for the margin 7 of the printing plate,and a vertically moving clamp 16 having a hook shaped under surfaceengages the overhanging lower edge of the margin by means of its lip 8,and securely holds the forward end of the plate. The clamp is depressedinto action by screws 17 entering threaded openings in the tongue 13.The rear block 10 is somewhat differently formed, although it has atongue 14 similar to the tongue 13 and a clamp 18 similar to clamp 16and screws 19 entering the tongue.

Instead of the sloping surface 15, block 10 has a vertical recess 20extending from side to side of the block and a raised shoulder 21 in thebottom of the recessat the rear thereof. The margin 7 at the rear of theplate extends over the recess 20 in a downward direction to itsengagement with the clamp 18 as plainly indicated and is supported oversaid recess by a movable plate 22, the shape of which clearly appears inFig. 4. It has a lip 23 on its under surface, which is adapted to setdownon the shoulder 21 of the block, so that the plate may freely rockon the same in accordance with the extent of the depression of margin 7by the clamp 18. The rocking of plate 22 caused by the clamp tends toswing the upper edge of the plate against the margin of the printingplate and thus to cause tension upon the plate. The plate 22 can rockfreely and independently of the clamp except as it is held by thepressure of the plate thereupon when the clamp is tightened. The plate22 is of spring metal, and hence, can be strained by the clamp andthereby enabled not only to hold the plate tightly but also to maintainsuch tension on it as will prevent any bulging or gathering at the rearend of the plate under the ironing operations of the impressioncylinder.

It will be understood that during impressions the cylinder rolling onthe printing surface tends to iron the plate toward the rear end of theform, and this is apt to produce a slight buckle in the printingsurface; but by reason of the spring or resiliency of the plate 22 thistendency of the printing surface to buckle is obviated and it is ke tunder tension and flat in advance of t e cylinder during the entireimpression, thus preventing any slur at the end of impression. The plate22 is so formed that the printing plate 6 will not be lifted off of theblocks when the clamp 19 is tensioned; in other words this spring plate22 being so fulcrumed that it cannot lift the printing plate above theimpression line.

The plate is preferably provided with cars 24 at each end, which can beentered in openings formed in the side plates 25 as seen at Fig. 3,secured to the end blocks as shown and thus be'prevented from losing itsposition in the blocks. The blocks 9 as well as blocks 10 are preferablyprovided with side plates 25.

I claim 1. A flexible integral printing plate having transverse channelsin its upper side beyond the printing surface forming thin integralmargins with projecting lips on their upper sides and at their outeredges for engagement with the clamping devices, said margins beingpreliminarily bent down to facilitate engagement of the lips with theclamps.

2. In combination, a support, a printing surface thereon comprising aflexible printing plate, means securing one end of said printing plateto the support, a clamp securing the other end of said printing plate,and a freely rocking plate interposed between the latter clamp and theadjacent edge of the support, said freely rocking plate engaging theunder surface of the printing plate and holding it under tension.

3. In combination, a flexible printing plate having a printing surfaceand margins at its ends beyond the printing surface for engagement withclamping devices; with a support for said printing plate, clamps at theends of said, support engaging the ends of said plate, and a freelyrocking plate interposed between the clamp at one end of the support andthe adjacent edge of the support, and adapted to hold the printing plateunder tension.

4:. In combination, a support, a printing surface thereon comprising aflexible printing plate having a printing surface and a clamp engagingmargin, a clamp adjacent the end of the support engaging said margin ofthe printing plate and a freely rocking plate interposed between theclamp and support and engaging the under surface of said margin andadapted to keep the printing plate under constant tension.

5. In combination, a flexible printing plate having reduced integralmargins at its ends, a support for said printing plate, and adjustableclamps at opposite ends of said support engaging said flexible marginsto secure the printing plate; with a freely rocking tensioning plateintermediate one clamp and the adjacent end ofthe support and engagingthe under surface of the adja-- cent flexible margin of the printingplate, and adapted to maintain the printing plate under tension.

6. In combination a flexible printing-plate having reduced flexiblemargins beyond the printing surface, provided with clamp en'- gaginglips, a support for said plate, ad-

justable clamps at the opposite end of said support engaging the lips ofthe flexible margins to secure the printing plate, and a rockingspring-plate at one end of the support engaging the under surface of theadjacent flexible margin of the printing plate, and adapted to tensionthe latter.

7. In combination a support having a sloping surface at one end and ashoulder at its other end, a rocking plate resting on sai shoulder, andplate clamps secured to the end of the support adjacent said surface;with a flexible printing-plate having its opposite ends respectivelybent down over the sloping surface and over the rocking-plate, andengaged by the clamps. V

8. In combination a printing surface support having a sloping surface atone end an a shoulder at its other end, a rocking-plate resting on saidshoulder and movable clamps secured to the ends of the support; with aflexible printing plate having reduced integral margins on its ends bentdown over the sloping surface and over the rockingplate and engaged bythe clamps, substantially as described.

9. In combination with the supporting blocks, of printing plate clamps16 and 18, both having overhanging hook edges, said clamps being securedeach to one of the blocks, a rocking plate adjacent the clamp 18 andunderlying the edge of the printing plate, a support for said rockingplate, and a printing plate having end margins with turned up lipsengaging the hook edges of the clamps.

MICHAEL A. DROITCOUR.

Witnesses: I

H. M. MUNDAY, Enw. S. EVARTS.

